diff options
Diffstat (limited to 'src/field_10x26_impl.h')
| -rw-r--r-- | src/field_10x26_impl.h | 69 |
1 files changed, 43 insertions, 26 deletions
diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h index 7b8c079608..234c13a644 100644 --- a/src/field_10x26_impl.h +++ b/src/field_10x26_impl.h @@ -38,10 +38,6 @@ static void secp256k1_fe_verify(const secp256k1_fe *a) { } VERIFY_CHECK(r == 1); } -#else -static void secp256k1_fe_verify(const secp256k1_fe *a) { - (void)a; -} #endif static void secp256k1_fe_normalize(secp256k1_fe *r) { @@ -325,17 +321,17 @@ static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b) { } static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) { - int i; - r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0; - r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0; - for (i=0; i<32; i++) { - int j; - for (j=0; j<4; j++) { - int limb = (8*i+2*j)/26; - int shift = (8*i+2*j)%26; - r->n[limb] |= (uint32_t)((a[31-i] >> (2*j)) & 0x3) << shift; - } - } + r->n[0] = (uint32_t)a[31] | ((uint32_t)a[30] << 8) | ((uint32_t)a[29] << 16) | ((uint32_t)(a[28] & 0x3) << 24); + r->n[1] = (uint32_t)((a[28] >> 2) & 0x3f) | ((uint32_t)a[27] << 6) | ((uint32_t)a[26] << 14) | ((uint32_t)(a[25] & 0xf) << 22); + r->n[2] = (uint32_t)((a[25] >> 4) & 0xf) | ((uint32_t)a[24] << 4) | ((uint32_t)a[23] << 12) | ((uint32_t)(a[22] & 0x3f) << 20); + r->n[3] = (uint32_t)((a[22] >> 6) & 0x3) | ((uint32_t)a[21] << 2) | ((uint32_t)a[20] << 10) | ((uint32_t)a[19] << 18); + r->n[4] = (uint32_t)a[18] | ((uint32_t)a[17] << 8) | ((uint32_t)a[16] << 16) | ((uint32_t)(a[15] & 0x3) << 24); + r->n[5] = (uint32_t)((a[15] >> 2) & 0x3f) | ((uint32_t)a[14] << 6) | ((uint32_t)a[13] << 14) | ((uint32_t)(a[12] & 0xf) << 22); + r->n[6] = (uint32_t)((a[12] >> 4) & 0xf) | ((uint32_t)a[11] << 4) | ((uint32_t)a[10] << 12) | ((uint32_t)(a[9] & 0x3f) << 20); + r->n[7] = (uint32_t)((a[9] >> 6) & 0x3) | ((uint32_t)a[8] << 2) | ((uint32_t)a[7] << 10) | ((uint32_t)a[6] << 18); + r->n[8] = (uint32_t)a[5] | ((uint32_t)a[4] << 8) | ((uint32_t)a[3] << 16) | ((uint32_t)(a[2] & 0x3) << 24); + r->n[9] = (uint32_t)((a[2] >> 2) & 0x3f) | ((uint32_t)a[1] << 6) | ((uint32_t)a[0] << 14); + if (r->n[9] == 0x3FFFFFUL && (r->n[8] & r->n[7] & r->n[6] & r->n[5] & r->n[4] & r->n[3] & r->n[2]) == 0x3FFFFFFUL && (r->n[1] + 0x40UL + ((r->n[0] + 0x3D1UL) >> 26)) > 0x3FFFFFFUL) { return 0; } @@ -349,21 +345,42 @@ static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) { /** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */ static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a) { - int i; #ifdef VERIFY VERIFY_CHECK(a->normalized); secp256k1_fe_verify(a); #endif - for (i=0; i<32; i++) { - int j; - int c = 0; - for (j=0; j<4; j++) { - int limb = (8*i+2*j)/26; - int shift = (8*i+2*j)%26; - c |= ((a->n[limb] >> shift) & 0x3) << (2 * j); - } - r[31-i] = c; - } + r[0] = (a->n[9] >> 14) & 0xff; + r[1] = (a->n[9] >> 6) & 0xff; + r[2] = ((a->n[9] & 0x3F) << 2) | ((a->n[8] >> 24) & 0x3); + r[3] = (a->n[8] >> 16) & 0xff; + r[4] = (a->n[8] >> 8) & 0xff; + r[5] = a->n[8] & 0xff; + r[6] = (a->n[7] >> 18) & 0xff; + r[7] = (a->n[7] >> 10) & 0xff; + r[8] = (a->n[7] >> 2) & 0xff; + r[9] = ((a->n[7] & 0x3) << 6) | ((a->n[6] >> 20) & 0x3f); + r[10] = (a->n[6] >> 12) & 0xff; + r[11] = (a->n[6] >> 4) & 0xff; + r[12] = ((a->n[6] & 0xf) << 4) | ((a->n[5] >> 22) & 0xf); + r[13] = (a->n[5] >> 14) & 0xff; + r[14] = (a->n[5] >> 6) & 0xff; + r[15] = ((a->n[5] & 0x3f) << 2) | ((a->n[4] >> 24) & 0x3); + r[16] = (a->n[4] >> 16) & 0xff; + r[17] = (a->n[4] >> 8) & 0xff; + r[18] = a->n[4] & 0xff; + r[19] = (a->n[3] >> 18) & 0xff; + r[20] = (a->n[3] >> 10) & 0xff; + r[21] = (a->n[3] >> 2) & 0xff; + r[22] = ((a->n[3] & 0x3) << 6) | ((a->n[2] >> 20) & 0x3f); + r[23] = (a->n[2] >> 12) & 0xff; + r[24] = (a->n[2] >> 4) & 0xff; + r[25] = ((a->n[2] & 0xf) << 4) | ((a->n[1] >> 22) & 0xf); + r[26] = (a->n[1] >> 14) & 0xff; + r[27] = (a->n[1] >> 6) & 0xff; + r[28] = ((a->n[1] & 0x3f) << 2) | ((a->n[0] >> 24) & 0x3); + r[29] = (a->n[0] >> 16) & 0xff; + r[30] = (a->n[0] >> 8) & 0xff; + r[31] = a->n[0] & 0xff; } SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) { |